title: Complex sleep apnoea in congestive heart failure.
abstract: BACKGROUND
  Sleep disordered breathing is common and of prognostic significance in patients with congestive heart failure (CHF). Complex sleep apnoea (complexSA) is defined as the emergence of central sleep apnoea during continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnoea (OSA). This study aims to determine the prevalence and predictors for complexSA in patients with CHF with OSA, and to assess the effects of treatment with adaptive servoventilation.
  
  
  METHODS
  192 patients with CHF (left ventricular ejection fraction (LVEF) ≤45%, New York Heart Association (NYHA) class ≥2) and OSA (apnoea-hypopnoea index (AHI) ≥15) were investigated using echocardiography, cardiopulmonary exercise testing, measurement of hyperoxic, hypercapnic ventilatory response, 6 min walk test and measurement of N-terminal pro-brain natriuretic peptide (NT-proBNP) prior to CPAP introduction. If patients demonstrated complexSA (AHI >15/h with <10% obstructive events) during CPAP titration, adaptive servoventilation was introduced and the investigations were repeated at 3 monthly follow-up visits.
  
  
  RESULTS
  ComplexSA developed in 34 patients (18%) during CPAP titration. After adjustment for demographic and cardiac parameters, measures of CO(2) sensitivity (higher hyperoxic, hypercapnic ventilatory response) were independently associated with complexSA. Patients using adaptive servoventilation had improved AHI, NYHA class, NT-proBNP concentration, LVEF, hyperoxic, hypercapnic ventilatory response, oxygen uptake during cardiopulmonary exercise testing and the relationship between minute ventilation and the rate of CO(2) elimination (VE/Vco(2) slope) at last individual follow-up (14±4 months).
  
  
  CONCLUSIONS
  There is a high prevalence of complexSA in patients with OSA and CHF, and those who develop complexSA have evidence of higher respiratory controller gain before application of CPAP. Treatment with adaptive servoventilation effectively suppressed complexSA and had positive effects on cardiac function and respiratory stability.
authors.affiliation: Department of Cardiology, Heart and Diabetes Centre NRW, Ruhr University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bitter
authors.forename: Nina
authors.initials: N
authors.lastname: Westerheide
authors.forename: Mohammed Sajid
authors.initials: MS
authors.lastname: Hossain
authors.forename: Roman
authors.initials: R
authors.lastname: Lehmann
authors.forename: Christian
authors.initials: C
authors.lastname: Prinz
authors.forename: Astrid
authors.initials: A
authors.lastname: Kleemeyer
authors.forename: Dieter
authors.initials: D
authors.lastname: Horstkotte
authors.forename: Olaf
authors.initials: O
authors.lastname: Oldenburg
mesh_terms: D000368:Aged; D045422:Continuous Positive Airway Pressure; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications* / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011175:Positive-Pressure Respiration / Q000379:methods; D012307:Risk Factors; D020182:Sleep Apnea, Central / Q000209:etiology* / Q000628:therapy; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000628:therapy; D016896:Treatment Outcome; D014463:Ultrasonography